Index indicator for plug-in units



Nov. 3, 1964 F. c. CARY 3, 5

INDEX INDICATOR FOR PLUG-IN UNITS Filed May 31, 1960 3 5 2 6f 6o 6a 9 flfl INVENTOR.

FREDERICK C. CARY United States Patent 3,155,862 INDEX INDICATORFOR PLUG-IN UNITS Frederick Charles Cary, Toronto, Ontario, Canada,

assignor to Canadian General Electric Company,

Limited, Toronto, ()ntario, Canada, a company of Canada Filed May 31, 1960, Ser. No. 32,724 2 Claims. (Cl. 313-109.5)

This invention relates to means for facilitating the insertion of an indexed plug-in'device, such as, for example, an electron discharge device, into a socket adapted to receive the device.

As is well-known, many electron discharge devices or electron tubes, as they are commonly called, are constructed with lead-in conductors extending through the base portion of the envelope of the electron tube. The portions of the lead-in conductors external to the envelope are adapted to fit into a cooperating socket. Receptacles are provided in the socket to receive the lead-in conductors, and various difierent voltages may be applied to different receptacles. Since each lead-in conductor may be internally connected to different components of the electron tube, e.g. the plate, cathode, grid, suppressor and screen electrodes, and if the cathode is indirectly heated, the heater, and each of these components generally requires a different voltage applied thereto via the socket receptacles, it is essential that some indexing means he provided on both the socket'and the electron tube to ensure that the electron tube can only 'be insertedinto the socket in one way. Many indexing means, some of which will be discussed later, have been developed for this purpose. The problem with such indexing means, however, is that generally they are not visible when one is looking at the top of the electron tube, as is usually the case when one is trying to position an electron tube in its cooperating socket. In order to position some of such electron tubes in their sockets, one must look at the base of the electron tube, determine the position of the indexing means, turn the electron tube over, remember the position of the indexing means, correlate the remembered position of the indexing means with the cooperating related indexing means on the socket, if necessary turn the electron tube tube until it is believedthatsthe indexing means on it is in alignment with the indexing means on the socket, and insert the electron vtubelead-in conductors into the socket receptacles. This process may have to be repeated several times before the" l'ead-in' conductors will fit .into .the receptacles in the socket. This process can be simplified, of course, if one can look at the electron tube or other plug-in device from the side while positioning it in the socket, since, in this case, the indexing means on both the plug-in device and the socket are visible. Unfortunately, however, in most cases it is not possible to view the plug-in device from the side when inserting it in a socket, as, for instance, when one is replacing an electron tube located at the front of a television receiver, or an electron tube which is surrounded by other electron tubes or electrical components such as transformers.

It is therefore an object of my invention to provide an indexed plug-in device having means thereon adapted to visibly indicate on the upper surface of the device the position of the indexing means located on the base of the device, thereby facilitating the insertion of the plug-in device in its cooperating indexed socket.

Other objects and advantages of my invention will become apparent from the following disclosure taken in conjunction with the drawings in which:

FIGURES 1 and 2 are perspective views of electron discharge devices embodying my invention,

FIGURE 3 is a top elevation of the electron discharge device shown in FIG. 1,

ice

FIGURE 4 is a perspective view of a plug-in device embodying my invention, and

FIGURES 5 to 7 are bottom elevation views of plug-in devices such as electron tubes. N

In brief, a plug-in device embodying my invention comprises an envelope having upper and lower end wall portions. Through the lower end wall portion of the envelope extend a plurality of lead-in conductors the portions of which that are external to the envelope being adapted to be inserted into receptacles in a mating socket for the device. Indexing means are provided to ensure correct positioning of the lead-in conductors in the socket receptacle s. Means are provided on the upper end wall portion of the envelopeto visibly indicate the position of the indexing means to an observer who is looking at the top of the device. I

Referring now to FIGURE 1, I have shown an electron tube 2 having an envelope comprising a side wall portion 3 and upper andlower end wall portions 4 and 5 respectively. A plurality of lead-in conductors tin-6g extend through lower end wall portion 5.' On upper end wall portion 4 there is tipped off exhaust tubulat-ion 7. Also positioned on upper end wall portion 4 is an index indicator 8 which may be, for example, a dotof paint. Index indicator 8 is positioned opposite the gap between lead-in conductors 6a and 6g preferably along a line parallel to the long axis of the envelope. 7 i

Referring now to FIGURE 2, I have depicted an electron tube 2 having a side wall portion 3 and an upper end wall portion 4'. The lower end wall portion is not shown as it is inserted in' a base 10. Extending through base iii and the lower end wall portion are a plurality of leadin conductors 6. A cylinder 11 is affixed to base 10, and part of cylinder 11 is formed into an index key 12. On upper end wall portion 4 is a dimple 9. Dimple 9 is in alignment with index key 12.

FIGURE 3 requires little description except to point out that as well as providing index indicating means 8 such as a painted dot on upper end wall portion 4 to facilitate the positioning of electron tube 2 in its socket, one may also letter the tube designation numbers, in this case 6CB6, on upper end Wall portion 4 in order'to permit identification of electron tube 2 without removing it, from its socket. r

.In FIG. 4 I have shown a plug-in device 13 having a side Wall portion} and upper and lower end wall portions 4 and 5 respectively. Extending through, lower end wall portions are a pluralityoflead-in conductors 6a6g. Onupper end wall portion 4. is an index indicator 8 which in this case is a painted form'in the shape of an arrow. Index indicator 8 is opposite the gap between lead-in conductors 6aand 6g. Any type of circuitry or components may be located inside plug-in device 13. For example, plug-in device 13 may be an oscillator, amplifier or a static switching unit.

FIGURES 5-7 show three suitable means for indexing plug-in devices to ensure correct positioning in a cooperating socket.

In FIGURE 5 two sets of lead-in conductors are provided. The pair of lead-in conductors labelled 6b are both larger in diameter and spaced further apart than the pair of lead-in conductors 6a. Since a socket for receiving a plug-in device such as is shown in FIGURE 5 has two large diameter receptacles spaced far apart and two small diameter receptacles spaced close together in juxtaposition to receive lead-in conductors 6a and 6b, it is apparent that the plug-in device can only be inserted in the socket inone way. In this case, therefore, all

lead in conductors and the spacing therebetween contribute to the indexing of the plug-in device.

FIGURE 6 is a bottom elevation of electron tube 2 shown in FIGURE 2. The mating socket for electron 3 tube 2 contains a keyed aperture which is the same shape as cylinder 11 and index key 12. In this case, the indexing means is index key 12 which permits insertion of electron tube 2 in only one way in its cooperating socket.

FIGURE 7 is a bottom elevation of electron tube 2 shown in FIGURE 1 or plug-in device 13 shown in FIG- URE 4. It is apparent that 1eadin conductors 611-6) are regularly spaced with respect to each adjacent lead-in conductor. Lead-in conductors 5a and 6g are not regularly spaced however. The configuration of lead-in conductors fizz-6g is referred to in the art as an odd pin base on an even pin circle. In the particular case shown, seven lead-in conductors 6a6g are spaced on a circle divided into eight parts. Thus the gap between lead-in conductors 6a and 6g is approximately twice the gap between any other two adjacent lead-in conductors. The mating socket for electron tube 2 shown in FIGURE 7 is similarly constructed with the receptacles for lead-in conductors 6a6g being spaced in identical configuration to lead-in conductors 611-65,. It is apparent that an electron tube so constructed can only be inserted in its cooperating socket in one way. The indexing function is performed by lead-in conductors 6a and 6g.

It is obvious from the figures, and especially FIGURE 3, that when one wishes to insert a plug-in device such as electron tube 2 in its socket, the indexing means are not visible when one is looking at the top of the plug-in device as is generally the case. In accordance with my invention, therefore, I provide means on upper end wall portion 4 to visibly indicate to an observer looking at the upper surface of the plug-in device, the position of the invisible indexing means on the bottom of the device. As shown in FIGURE 1, this may be accomplished by providing an indexing indicator 8 such as a painted dot on upper end wall portion 4 opposite the gap between lead-in conductors 6a and 6g. The painted dot is so positioned to indicate to an observer the approximate location of adjacent lead-in conductors 6a and 6g, or, in other words, the approximate location of the tube indexing means.

While in FIGURES 1 and 4 I have shown a painted dot and a painted arrow respectively as serving the index indicating function, it will be apparent that any type of painted form would be equally suitable. It should also be noted that while I have used the word painted, this word is to be interpreted in its broadest sense and covers such alternatives, for example, as stencilling, stamping, printing or transferring index indicating form 8 onto upper end wall portion 4.

As another embodiment of my invention, a dimple 9 as shown in FIGURE 2 may be used as an index indicator. Dimple 9 may be either on or in upper end wall 4 i.e. it may project outwardly from the surface of the envelope or be an indentation therein. As shown in FIGURE 2, dimple 9 is positioned in alignment with key 12, the electron tube indexing means,

It is apparent that plug-in devices embodying my invention may be simply and quickly inserted in their cooperating sockets. A person wishing to insert a plug-in device embodying my invention into its cooperating socket need only look at the socket, determine the position of the socket indexing means, align the socket indexing means with the index indicator on the plug-in device, and insert the plug-in device into the socket. There is no need to remember the position of the invisible index on the plug-in device.

Plug-in devices such as shown in FIGURE 5 in which there is no one component which serves as an index may be dealt with by choosing one, or if necessary, two components as an index. For instance, the two larger lead-in conductors 6b could be chosen as an index, and two index indicating means positioned in alignment with leadin conductors 6b on upper end wall portion 4 of the envelope. Once such a convention has been adopted, however, it should be adhered to consistently.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A plug-in device having an envelope comprising upper and lower end wall portions and a side wall portion, a plurality of lead-in conductors extending through said lower end wall portion of said envelope, the portions of said lead-in conductors external to said plug-in device being adapted to be located in a socket, all but two adjacent lead-in conductors being substantially regularly spaced with respect to each adjacent lead-in conductor, and index indicating means positioned on said upper end wall portion of said envelope to visibly indicate the approximate location of said two adjacent lead-in conductors to an observer.

2. A plug-in device having an envelope comprising upper and lower end wall portions and a side wall portion, a plurality of lead-in conductors extending through said lower end wall portion of said envelope, the portions of said lead-in conductors external to said plug-in device being adapted to be located in a socket, said lead-in conductors being odd in number but spaced on an evcnpip circle whereby all but two adjacent lead-in conductors are substantially regularly spaced with respect to each adjacent lead-in conductor, and index indicating means positioned on said upper end wall portion of said envelope to visibly indicate the approximate location of said two adjacent lead-in conductors to an observer.

References Cited in the file of this patent UNITED STATES PATENTS 2,528,246 Roovers et al. Oct. 31, 1950 FOREIGN PATENTS 883,464 France Mar. 22, 1943 61,789 Denmark Jan. 10, 1944 

1. A PLUG-IN DEVICE HAVING AN ENVELOPE COMPRISING UPPER AND LOWER END WALL PORTIONS AND A SIDE WALL PORTION, A PLURALITY OF LEAD-IN CONDUCTORS EXTENDING THROUGH SAID LOWER END WALL PORTION OF SAID ENVELOPE, THE PORTIONS OF SAID LEAD-IN CONDUCTORS EXTERNAL TO SAID PLUG-IN DEVICE BEING ADAPTED TO BE LOCATED IN A SOCKET, ALL BUT TWO ADJACENT LEAD-IN CONDUCTORS BEING SUBSTANTIALLY REGULARLY SPACED WITH RESPECT TO EACH ADJACENT LEAD-IN CONDUCTOR, AND INDEX INDICATING MEANS POSITIONED ON SAID UPPER END WALL PORTION OF SAID ENVELOPE TO VISIBLY INDICATE THE APPROXIMATE LOCATION OF SAID TWO ADJACENT LEAD-IN CONDUCTORS TO AN OBSERVER. 